Change-speed control



May 9, 1939. P. L. TE'NNEY ET AL 2,157,249

' CHANGE-SPEED CONTROL Filed Sept. 5, 1936 a Sheets-Sheet 1 May 9, 1939. P. L. TENNEY Er AL 2,157,249

, CHANGE-SPEED CONTROL Filed Sept. 5, 1936- 3 Sheets-Sheet 3 Patented May 9, 1939 UNITED STATES PATENT OFFICE Flint, Mich.,- assignors to General Motors Corporation, Detroit, Mich, a corporation of Dela- Application September 5, 1936, Serial No. 99,560

2 Claims.

This invention relates to change speed transmission gearing.

A primary object is to provide parallel but offset input and output shafts.

Another object is to provide a transmission wherein the gear trains themselves are so arranged as to avoid the need for gearing, in addition thereto, to accommodate a driven shaft which is necessarily out of alignment with the input shaft of the transmission.

Another object is to arrange gear trains in a way to provide four forward and two reverse driving ratios with a. minimum of gear trains; with synchronism of each driving ratio by the use of only two synchromesh units; with conventional shifting and a transmission wherein remote control is easily arranged.

Another object is to produce a transmission useful where the driving axle is directly alongside or under the engine or where for any reason it is desired to have the output shaft out of alignment with the crank shaft. Such an arrangement makes it possible for the output shaft to clear the clutch and flywheel housing.

The invention may be found particularly useful for front drive installations or for driving rear wheels with rear engine mountings.

Other objects and advantages will be understood from the following description.

In the accompanying drawings, Fig. 1 is a transverse section through the novel change speed transmission.

Fig. 2 is a section on line 2-2 of Fig, 1.

Fig. 3 is a view in elevation showing the manually operable shiftlevers and connections.

Fig. 4 is a view as seen from line 4-4 of Fig. 3.

Fig. 5 is a perspective of parts shown in Fig. 3 but in. disassembled relation.

In the drawings, the input shaft 5 from the clutch housing 1 enters the change speed housing 9. In opposite walls the shaft 5 is supported by antifriction bearings II and [3. Gears l5 and I! are rotatably supported on shaft 5 by bearings l9. Between these gears the shaft is splined at 2| for a double jaw clutch member 23 having end teeth 25 and 21 for engagement with clutch teeth 29 and 3| on gears I5 and I1, respectively. The clutch 23 may be moved to and fro by a suitable radial extension such as 33 engaged by a fork 35. This movement also moves a synchronizer 31 having conical end faces cooperating with like faces on the gears l5 and I1 adjacent the clutches 29 and 3|. The structure and function of such synchronizing devices is well known and need not be more fully described. When the clutch 33 is moved to the left (Fig. 1) gear is locked to shaft 5 and when moved to the right gear I5 is released and gear ll becomes operative.

A lay shaft 39 rotates within antifriction bearings 4| and 43, the former being adjacent a removable wall cover 45. This shaft has four gears. Gear 41 meshes constantly with gear I5 as does gear 49 with gear 11. Intermediate gears 5| and 53 are shown on this shaft. Gear 55 on an idler shaft 51 is also shown.

A splined output shaft 59 is journal'ed on bearings 6| and B3 in the housing walls. A cover 65 covers one end of the shaft and is secured by fastening means 61. An oil seal 69 carried by a ring 1| surrounds the other end of the shaft and is secured by fastening means 13. It will be observed that a coupling member 15 is secured by fastener 11 to one end of shaft 59 and that the shaft is so far removed from shaft 5 that it will be clear of the clutch and flywheel housing 1. In some installations the shaft 59 will be arranged to extend in the opposite direction with the coupling member to the right of the housing in which case the parts 65 and II will be interchanged. on shaft 59 is slidably splined a double gear having two gear elements 19 and BI equipped with a collar 83 for a fork 85. Gear 19 may be moved by its fork to mesh with gear 41 or gear BI may be moved into engagement with gear 5|. A fur ther movement of the double gear brings 8| into mesh with idler 55.

It is intended that a transverse movement of the manually operable shift lever shall shift the double gear 19-8! to the right or left and that thereafter a longitudinal movement of the shift lever shall shift clutch 33 for engagement with either gear l5 or I'I'.

For moving the fork 85 there is rotatably supported in the casing wall a rock shaft 81 having an outer arm 89 and an inner arm 9|, the latter carrying a crank pin 93 received within a slot 95 of the fork. A second rock shaft is rotatably supported in a casing wall boss 91. It has an outer arm 99 and an inner arm llll, the latter with a crank pin I03 engaging a slot I05 in the end of fork 35. Forks 35 and 85 have conventional locating spring detent devices I 91 associated with the rails I09 and l H on which they slide. Also, a plate H3 is secured to the casing wall at H5 and lies between arm IUI and an extension of arm 9|. Plate H3 has a hole therethrough in which is a ball I I1. There are pockets as at I I9 in the arm and arm extension arranged opposite each other in the neutral position of the arms and forks but when one arm is rocked to determine an operative position of its fork the ball H1 is pushed partly from the hole in plate I I3 and thus locks the other fork.

Figs. 3, 4 and 5 show how the ratio changes may be made by a manually operable shift lever positioned remote from the gear box. In these figures are seen the housing 9 and the arms 89 and 99. The manually operable shift lever is marked I2I and is equipped with a knob I23. A dome I25 is supported on a base I21. A shift lever fulcrum I21 of conventional design provides for both transverse movements of the lever I2I (through the plane of the paper) and longitudinal movements. A rectangular plate I29 has openings I3I for the passage of fastening means I33 by which plate I29 is secured to base I21. This plate has a corner extension I35 to which is pivoted at I31 a lever I39. One end of the lever is connected at MI to a link I43, the link, at its other end, being pivoted to lever arm 89. The plate I29 has downturned tongues I45 and I41 which may be formed with slots such as I49 for the guidance of a sliding plate I5I. The plate I5I has at one end a rectangular opening I53 to receive a lug I55 turned up from the end of lever I39. Transverse reciprocation of plate I5I rocks lever I39 and the resulting axial movement imparted to link I43 rocks lever 89 and shifts the double gear 19-8I. To effect such reciprocation of plate I5I, it has an elongated rectangular opening I51. The lever I2I extends through this opening and, when transversely rocked, engages one or the other of the side walls of the opening and reciprocates the plate. The long dimension of slot I51 is to accommodate longitudinal pivotal movement of lever I2I. An opening in plate I29 is shaped as shown in Fig. 5. It has an elongated slot I59, a second elongated slot IBI', the slots being separated by tongues I53. The lever IZI extends through the opening in plate I29 as well as through opening I51 and its lower end is connected to link I5I, the latter being connected to lever arm 99. In this way longitudinal rocking of lever IZI rocks lever 99 and renders active gear train I5, 41 or gear train I1, 49. It will be seen that the opening I51 of plate I5I may be positioned to lie beneath slot I59 by a transverse rocking of the lever I2I. This transverse movement has rocked the lever I39 to position gear 19 in engagement with gear 41. A longitudinal movement of the lever I2I in one direction or the other causes gear 41 to be driven at one or another of two speeds, depending upon. whether gear I5 .or I1 is clutched to shaft 5. The lever I 2| may then be returned to its midlength position, re-

leasing the drive of the gears on shaft 39. It may then be shifted transversely, releasing the drive of the gears on shaft 59, pass between tongues I63 and enter the slot ISI. When fully entered in slot IBI, it has moved lever I39 sufficiently to engage gear BI with gear 5|, whereupon the longitudinal rocking of the lever IZI may again drive the gears of shaft 39 at either of two speeds. Thus four forward speeds are obtained.

A tongue I65 spaces slot I6I' from a further slot I61. Normally the lever is prevented from being shifted transversely into slot I 61 by a lug I69 slidable on the lever I2I and held by a spring I1I in position to engage the tongue I65. When the lug I69 is lifted by a tension rod I13 and hand hold I15, the slot I61 may be reached. In doing so, gear 55 may be engaged by gear 8 I. The slot I61 permits a longitudinal movement of the hand lever either in one direction only as shown, if but one reverse speed is desired, or in both directions if two reverse driving ratios are preferred. This latter arrangement is had by shaping slot I61 to correspond with slots I59 and IBI.

By the arrangement thus shown and described the several objectives are obtained. The output shaft is positioned where it will clear the clutch housing and thus avoid the use of added gear trains in many installations when conventional gear boxes would require an additional gear to dispose the output shaft away from adjacent mechanism. By the use of eight gears only, four forward and two reverse ratios are provided with synchromesh for all ratios, this being accomplished by the use of but two synchromesh devices.

We claim:

1. For use with transmission mechanism having shiftable members to effect ratio changes, spaced parallel rockshafts extending transversely of and into said transmission mechanism, arms on said rockshafts within said transmission mechanism, connections between said arms and members whereby said arms when rocked move said shiftable members, other and external arms on said rockshafts, a manually operable shift lever, means including a link connected directly to said shift lever and to one of said rockshaft arms, a plate adapted to be reciprocated by said manually operated lever, a link connected to the second of said rockshaft arms and transmitting means between and connected to said last named link and said plate.

2. The invention defined by claim 1, together with a fixed plate having guiding means for said reciprocable plate, said guiding plate having H slot means for the passage of the manually operable lever and said reciprocable plate having a rectangular slot for the passage of the manually operable lever.

PERRY L. TENNEY. BENTON CATALINE. 

